1. Field of the Invention
The present invention relates to a substrate processing apparatus, for example, for performing coating processing of a resist solution, developing processing, and the like for a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display, or the like.
2. Description of the Related Art
In photolithography in a semiconductor device fabricating process, a resist is applied to the front face of a semiconductor wafer (hereinafter referred to as a wafer), the applied resist is subjected to exposure processing in accordance with a predetermined pattern and then developing processing, whereby the predetermined pattern of resist film is formed. Such a series of processing is performed by a system in which an aligner is connected to a coating and developing apparatus.
FIG. 13 is a plan view showing a conventional example of such an apparatus, and a substrate cassette C housing 25 substrates, for example, semiconductor wafers is carried into a cassette stage 1 of a cassette station 100. A coating block 110 and a developing block 120 are connected to the cassette station 100 in this order, and an aligner 140 is connected to the developing block 120 with an interface station 130 between them.
A wafer W in the cassette C on the cassette stage 1 is taken out by a delivery arm not illustrated, and then sent to the coating block 110 via a delivery table 10. In the coating block 110, the wafer W is coated with the resist in a coating unit 11, and then transferred by the route of a main arm A1.fwdarw.a delivery table 12.fwdarw.a main arm A2 in the developing block 120.fwdarw.a delivery table 13.fwdarw.the interface station 130.fwdarw.a carrying-in stage 14 of an aligner 140.fwdarw.a delivery arm 15.fwdarw.an exposure section 16, and exposed. Incidentally, in the coating block 110, before and after the coating of the resist, pre-processing and post-processing are respectively performed in a shelf unit 17a.
The exposed wafer W is transferred to the developing block 120 by the reverse route via a carrying-out stage 18 of the aligner 140, developed in a developing unit 19, and then transferred by the route of the main arm A2.fwdarw.the delivery table 12.fwdarw.the main arm A1.fwdarw.the delivery table 10.fwdarw.the cassette C. In the developing block 120, before and after the developing processing, pre-processing and post-processing are respectively performed in a shelf unit 17b.
Incidentally, since the processing speed of the aligner 140 is increasing in the aforesaid coating and developing apparatus, the processing number of wafers is required to be 150 or more in coating processing and developing processing, and hence a system provided with three coating units 11 and four developing units 14 and also provided with three antireflection film forming units each for forming an antireflection film as pre-processing of resist coating is under consideration.
In this case, it is considered that a pre-processing block is provided, for example, between the cassette station 100 and the coating block 110, and the antireflection film forming units and a main arm for transferring the wafer W, for example, are provided there.
Incidentally, in the aforesaid coating and developing apparatus, in some cases, an operator performs work for the units and the like inside the apparatus such as confirmation of the operations of the main arm A1 and the like, maintenance of the shelf units 17a and 17b, cleaning of the carrying-in stage 14 and the carrying-out stage 18 of the aligner 140, and the like. Meanwhile, in the aforesaid apparatus, spaces between the units in each block are eliminated as much as possible for the purpose of downsizing the apparatus and reducing occupied floor space. Accordingly, a space for maintenance by the operator is not secured in each block. As a result, the operator needs to do the aforesaid work from the outside of the apparatus, thereby causing disadvantages that the work is difficult, and thus maintenance and the like take a lot of time.
Further, in the aforesaid layout in which the pre-processing block is disposed between the cassette station 100 and the coating block 110, the distance between the cassette stage 1 and the aligner 140 is long. Thus, there is a disadvantage that efficiency of utilization of a clean room is deteriorated in the layout in which a depth from the cassette stage 1 is long since a transfer path for an automatic transfer robot for transferring the cassette C to the cassette stage 1 is formed along the cassette stage 1 and the transfer path is in the clean room.